A method for producing lubricating base oil by hydroprocessing of a fischer-tropsch synthesis soft wax

Abstract

The application discloses a hydrogenation isomerization catalyst and a method for hydrogenating a Fischer-Tropsch synthesis soft wax to obtain a lubricating oil base oil. The hydrogenation isomerization catalyst is a composite catalyst, which comprises catalyst I and catalyst II; the catalyst I is a molecular sieve catalyst with MTT structure loaded with platinum and / or palladium; the catalyst II is a molecular sieve catalyst with TON structure loaded with platinum and / or palladium; and the composite mode of the catalyst I and the catalyst II is that the catalyst I is located above the catalyst II. Based on the hydrogenation isomerization process of the noble metal / molecular sieve catalyst with the combined MTT structure and TON structure and specific catalytic performance, each component in the Fischer-Tropsch synthesis soft wax raw material, such as n-alkanes, branched alkanes and olefins, can be converted into isomerization products with high selectivity, so that the yield and performance of the base oil product are simultaneously improved.

Description

Technical Field

[0001] This application relates to a hydroisomerization catalyst and a method for producing lubricating oil base oil by hydrogenation of Fischer-Tropsch synthetic soft wax as raw material, belonging to the field of molecular sieve catalysis. Background Technology

[0002] Fischer-Tropsch wax is the main product of the Fischer-Tropsch synthesis reaction of syngas. It primarily contains long-chain alkanes and contains almost no sulfur, nitrogen, or aromatics, making it a high-quality feedstock for Group III+ lubricating oil base oils. Fischer-Tropsch soft wax can be hydroisomerized to produce high-viscosity-index Group III+ lubricating oil base oils. However, current technology requires recycling the soft wax to a hydrocracking reactor for diesel production, resulting in large quantities of naphtha and gaseous hydrocarbons as byproducts, wasting valuable Fischer-Tropsch wax resources that could be used to produce Group III+ lubricating oil base oils. The key technology for preparing high-grade lubricating oil base oils from Fischer-Tropsch wax products is to improve the low-temperature flow properties of the oil while maintaining a high viscosity index, i.e., lowering the pour point. This can be achieved through hydrocracking and hydroisomerization reactions. Compared to Fischer-Tropsch hard wax, Fischer-Tropsch soft wax, having undergone hydrocracking, has a significantly lower pour point and contains branched long-chain alkanes, as well as some olefins. In the process of producing Group III+ lubricating oil base oil through hydroisomerization, compared with normal long-chain alkanes, the branched long-chain alkanes in Fischer-Tropsch synthetic wax are more prone to cracking during further hydroisomerization. In addition, the olefins contained in the wax are also more likely to be adsorbed on the acidic sites of the catalyst and undergo excessive reaction (hydrocracking).

[0003] Therefore, producing Group III+ lubricating oil base oils in high yield using Fischer-Tropsch synthetic soft wax as a raw material is challenging. Summary of the Invention

[0004] According to one aspect of this application, a hydroisomerization catalyst is provided, which is based on a noble metal / molecular sieve catalyst with a combination of MTT and TON structures and specific catalytic properties in a hydroisomerization process. This enables the high-selectivity conversion of various components in the Fischer-Tropsch synthesis soft wax feedstock, such as n-chain long-chain alkanes, branched long-chain alkanes, and olefins, into isomers, thereby simultaneously improving the yield and performance of base oil products.

[0005] The hydroisomerization catalyst is characterized in that it is a composite catalyst comprising catalyst I and catalyst II;

[0006] Catalyst I is a molecular sieve catalyst with an MTT structure supported on platinum and / or palladium.

[0007] Catalyst II is a molecular sieve catalyst with a TON structure supported on platinum and / or palladium.

[0008] The catalyst I and catalyst II are combined in such a way that catalyst I is located on top of catalyst II.

[0009] Preferably, the total acid content in catalyst I is 100–400 μmol / g, the acid content on the outer surface is 10–50 μmol / g, the mesopore volume is 0.20–0.60 ml / g, and the loading of platinum and / or palladium (i.e., the mass percentage of platinum and / or palladium in catalyst I, calculated as the mass percentage of platinum and / or palladium metal elements contained in catalyst I) is 0.2–0.8 wt%.

[0010] Preferably, the total acid content in catalyst I is 280–360 μmol / g.

[0011] Preferably, the acid content on the outer surface of catalyst I is 20–40 μmol / g. More preferably, the acid content on the outer surface of catalyst I is 30–40 μmol / g.

[0012] Preferably, the mesopore volume of catalyst I is 0.30-0.50 ml / g. More preferably, the mesopore volume of catalyst I is 0.40-0.50 ml / g.

[0013] Preferably, the loading of platinum and / or palladium in catalyst I is 0.3-0.6 wt%. More preferably, the loading of platinum and / or palladium in catalyst I is 0.4-0.6 wt%.

[0014] Preferably, the molecular sieve with the MTT structure is selected from at least one of ZSM-23, Me-ZSM-23, EU-13, KZ-1, and ISI-4; wherein Me-ZSM-23 is a ZSM-23 molecular sieve doped with metal heteroatoms Me, and Me is selected from at least one of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd, or Ni.

[0015] Preferably, the total acid content in catalyst II is 200-600 μmol / g, the mesopore volume is 0.30-0.80 ml / g, and the loading of platinum and / or palladium (i.e., the mass percentage of platinum and / or palladium in catalyst II, calculated as the mass percentage of platinum and / or palladium metal elements contained in catalyst II) is 0.1-0.6 wt%.

[0016] Preferably, the total acid content in catalyst II is 300–500 μmol / g.

[0017] Preferably, the mesopore volume of catalyst II is 0.30-0.60 ml / g. More preferably, the mesopore volume of catalyst II is 0.35-0.55 ml / g.

[0018] Preferably, the loading of platinum and / or palladium in catalyst II is 0.2–0.5 wt%. More preferably, the loading of platinum and / or palladium in catalyst II is 0.3–0.5 wt%.

[0019] Preferably, the molecular sieve with the TON structure is selected from at least one of ZSM-22, Me-ZSM-22, Theta-1, KZ-2, ISI-1, and NU-10; wherein, Me-ZSM-22 is a ZSM-22 molecular sieve doped with metal heteroatoms Me, and Me is selected from at least one of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd, or Ni.

[0020] Optionally, the volume ratio of catalyst I to catalyst II is 1:10-10:1. Preferably, the volume ratio of catalyst I to catalyst II is 1:6-6:1.

[0021] According to another aspect of this application, a method for producing lubricating oil base oil by hydrogenation of Fischer-Tropsch synthetic soft wax as raw material is provided. The Fischer-Tropsch synthetic soft wax raw material enters the hydroisomerization reaction zone, where hydroisomerization and moderate cracking of the soft wax are completed on a hydroisomerization catalyst with a combination of MTT and TON structures and specific catalytic properties, to obtain hydroisomerized cracked oil. The hydroisomerized cracked oil enters the supplementary refining reaction zone for further processing, where the small amount of unsaturated olefins generated during the hydroisomerization cracking process are hydrogenated to saturate the crude product. The crude product is fractionated in an atmospheric / vacuum distillation tower to obtain base oil, diesel oil, naphtha, and other products.

[0022] The method for producing lubricating oil base oil by hydrogenation of Fischer-Tropsch synthetic soft wax as raw material is characterized by comprising the following steps:

[0023] 1) Fischer-Tropsch synthesized soft wax and hydrogen are mixed and introduced into the hydroisomerization reaction zone, where they come into contact with the hydroisomerization catalyst to carry out the hydroisomerization reaction, and hydroisomerized cracked oil is obtained.

[0024] 2) The hydroisomerized cracked oil enters the supplementary refining reaction zone and comes into contact with the supplementary refining catalyst, which further hydrogenates and saturates the hydroisomerized cracked oil to obtain the crude product.

[0025] 3) Fractionate the crude product to obtain products including lubricating oil base oil;

[0026] The hydroisomerization catalyst mentioned in step 2) is selected from the above-mentioned hydroisomerization catalysts; after the Fischer-Tropsch synthesis soft wax and hydrogen are mixed and enter the hydroisomerization reaction zone, they flow through catalyst I and catalyst II in sequence.

[0027] Optionally, the step of fractionating the crude product in step 3) is as follows: the crude product is sequentially fed into an atmospheric distillation tower and a vacuum distillation tower for fractionation to obtain lubricating oil base oil, naphtha and diesel.

[0028] Optionally, the supplementary refining catalyst in step 2) is a supported catalyst containing at least one active component selected from platinum, palladium, and iridium; the support is alumina and / or silica.

[0029] The active component, at least one of platinum, palladium, and iridium, is present in the supplementary refining catalyst at a mass content of 0.2 to 1.0 wt% (based on the mass percentage of platinum, palladium, and iridium metal elements contained in the supplementary refining catalyst).

[0030] Optionally, the reaction conditions for the supplementary purification reaction in step 2) are as follows:

[0031] The reaction temperature is 160–360℃, the hydrogen partial pressure is 3.0–18.0 MPa, and the feedstock volume hourly space velocity is 0.5–5.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 200:1 to 2000:1.

[0032] Preferably, the reaction temperature is 180–320°C, the hydrogen partial pressure is 5.0–15.0 MPa, and the feedstock volume hourly space velocity is 0.5–3 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1 to 1000:1.

[0033] Preferably, the n-alkane content in the Fischer-Tropsch synthesized soft wax in step 1) is not higher than 60%, the unsaturated hydrocarbon content is not lower than 0.5%, the initial boiling point is not lower than 220°C, and the final boiling point is not higher than 750°C.

[0034] The conditions for the hydroisomerization reaction are:

[0035] The reaction temperature is 200–450℃, the hydrogen partial pressure is 3.0–18.0 MPa, and the feedstock oil volume hourly space velocity is 0.4–4.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 200:1 to 2000:1.

[0036] Preferably, the n-alkane content in the Fischer-Tropsch synthesized soft wax in step 1) is not higher than 50%, the unsaturated hydrocarbon content is not lower than 1%, the initial boiling point is not lower than 260°C, and the final boiling point is not higher than 700°C.

[0037] The hydroisomerization reaction conditions are: temperature 300–400℃, hydrogen partial pressure 5.0–15.0 MPa, and feedstock volume hourly space velocity 0.5–2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1 to 1000:1.

[0038] Optionally, the reactor in the supplementary refining reaction zone in step 2) is connected in series with the reactor in the hydroisomerization reaction zone in step 1), and the hydroisomerized cracked oil flows from the hydroisomerization reactor into the supplementary refining reactor.

[0039] In this application, the total acidity of the catalyst was tested using pyridine as a probe molecule; the acidity of the outer surface was tested using 2,6-di-tert-butylpyridine as a probe molecule.

[0040] The beneficial effects of this application include, but are not limited to:

[0041] (1) It inhibits the cracking of olefins in Fischer-Tropsch synthetic soft wax, thus avoiding the loss of base oil yield caused by olefin cracking.

[0042] (2) The stepwise conversion of straight-chain and low-branched long alkanes in Fischer-Tropsch synthesis of soft wax was achieved by using a combination of specific catalysts;

[0043] (3) The process conditions are simple, there is no need to circulate the product of hydroisomerization, and the target product can be obtained in one pass;

[0044] (4) The base oil products obtained by this method have high yield and good performance. Attached Figure Description

[0045] Figure 1 This is a process flow diagram of the hydrogenation process for producing lubricating oil base oil from Fischer-Tropsch synthetic soft wax as described in this application. Detailed Implementation

[0046] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, all raw materials and reagents used in this application are commercially purchased and used directly without processing. The instruments and equipment used adopt the manufacturer's recommended scheme and parameters.

[0048] In the examples, the mesopore volume of the samples was determined using a Mack ASAP2420 physical adsorption instrument via nitrogen physical adsorption.

[0049] In this embodiment, the total acid content of the sample was determined using pyridine adsorption infrared spectroscopy (Py-IR): 10-20 mg of sample was weighed, pressed into a circular self-supporting sheet with a diameter of 13 mm, and placed in an in-situ infrared cell. The sample was first pretreated under vacuum at 350 °C for 30 min, then cooled to room temperature to record the spectrum of a blank sample. After pyridine adsorption, the sample was heated to 150 °C and pretreated under vacuum for 30 min, then cooled to room temperature to record the pyridine adsorption spectrum. The total acid content of the sample was calculated based on the characteristic peak area.

[0050] In this embodiment, the surface acidity of the sample was determined using 2,6-di-tert-butylpyridine adsorption infrared spectroscopy (DTBPy-IR): 10-20 mg of sample was weighed, pressed into a 13 mm diameter circular self-supporting sheet, and placed in an in-situ infrared cell. The sample was first pretreated under vacuum at 350 °C for 30 min, then cooled to 150 °C to record the spectrum of a blank sample. After adsorption of 2,6-di-tert-butylpyridine, the sample was vacuumed for 30 min, and the adsorption spectrum of 2,6-di-tert-butylpyridine was recorded. Subsequently, the sample was heated to 300 °C, vacuumed for 30 min, cooled to 150 °C, and the adsorption spectrum of 2,6-di-tert-butylpyridine was recorded. The total acidity of the sample was calculated based on the characteristic peak area.

[0051] In this embodiment, the infrared spectrum was measured using a Bruker Vertex70 infrared spectrometer.

[0052] As one specific implementation method, the technical solution of this application includes the following steps:

[0053] 1) The Fischer-Tropsch synthesis soft wax and hydrogen are mixed and introduced into the hydroisomerization reaction zone. In a fixed-bed reactor, it contacts the hydroisomerization catalyst. The reaction temperature is 200-450℃, the hydrogen partial pressure is 3.0-18.0 MPa, and the feedstock volume hourly space velocity is 0.4-4.0 h⁻¹. -1 The reaction was carried out under conditions where the hydrogen-to-oil volume ratio was 200:1-2000:1, to complete the hydroisomerization and moderate cracking of the Fischer-Tropsch synthesized soft wax, and to obtain hydroisomerized cracked oil.

[0054] 2) The hydroisomerized cracked oil obtained in step 1) enters the supplementary refining reaction zone. On the supplementary refining catalyst, the reaction temperature is 160–360℃, the hydrogen partial pressure is 3.0–18.0 MPa, and the feedstock volume hourly space velocity is 0.5–5.0 h⁻¹. -1 Under the condition of a hydrogen-to-oil volume ratio of 200:1-2000:1, further hydrogenation saturation of hydroisomerized cracked oil was completed to obtain crude product;

[0055] 3) The crude product obtained in step 2) enters the atmospheric / vacuum distillation tower and is fractionated to obtain naphtha, diesel oil, base oil and other products;

[0056] In step 1), the n-alkane content in the Fischer-Tropsch synthesized soft wax is not higher than 60%, the unsaturated hydrocarbon content is not lower than 0.5%, the initial boiling point is not lower than 220°C, and the final boiling point is not higher than 750°C.

[0057] The hydrogenation catalyst in step 1) includes catalyst I and catalyst II;

[0058] Wherein, catalyst I in step 1) is a catalyst prepared by supporting platinum and / or palladium on a molecular sieve with an MTT structure; catalyst II is a catalyst prepared by supporting platinum and / or palladium on a molecular sieve with a TON structure.

[0059] In step 1), the volume ratio of combined catalyst I to catalyst II is 1:10-10:1.

[0060] The method wherein, in step 1), the Fischer-Tropsch soft wax is the tail oil after hydrocracking of the hard wax generated by Fischer-Tropsch synthesis from syngas and separation of naphtha and diesel fractions. At room temperature, it is in the form of wax paste or viscous paste and is a mixture of n-chain long-chain alkanes, branched long-chain alkanes and unsaturated hydrocarbons (olefins).

[0061] The method wherein, in step 1), the content of n-alkane in the Fischer-Tropsch synthesized soft wax is not higher than 50%, the content of unsaturated hydrocarbons is not lower than 1%, the initial boiling point is not lower than 260°C, and the final boiling point is not higher than 700°C.

[0062] The method wherein, in step 1), the content of n-alkane in the Fischer-Tropsch synthesized soft wax is not higher than 40%, the content of unsaturated hydrocarbons is not lower than 3%, the initial boiling point is not lower than 280°C, and the final boiling point is not higher than 680°C.

[0063] The method wherein the hydroisomerization reaction conditions in step 1) are: temperature 300-400℃, hydrogen partial pressure 5.0-15.0 MPa, and feedstock volume hourly space velocity 0.5-2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1-1000:1.

[0064] The method wherein, in step 1), the molecular sieve having the MTT structure is one or more of ZSM-23, Me-ZSM-23 (Me = one or more of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd or Ni), EU-13, KZ-1 and ISI-4.

[0065] The method wherein, in step 1), the molecular sieve having the TON structure is one or more of ZSM-22, Me-ZSM-22 (Me = one or more of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd or Ni), Theta-1, KZ-2, ISI-1 and NU-10.

[0066] The method wherein, in step 1), the total acid content of catalyst I includes the acid content on the outer surface of the molecular sieve and the acid content inside the pores and channels of the molecular sieve.

[0067] The method wherein, in step 1), the total acidity of catalyst I is tested using pyridine as a probe molecule.

[0068] The method wherein, in step 1), the total acid content of catalyst I is 100–400 μmol (Pyridine) / g.

[0069] In the method described, the total acid content of catalyst I in step 1) is preferably 150–300 μmol (Pyridine) / g.

[0070] In the method described in step 1), the acidity of the outer surface of catalyst I is tested using 2,6-di-tert-butylpyridine as a probe molecule.

[0071] The method wherein, in step 1), the acid content of the outer surface of catalyst I is 10–50 μmol (2,6-Di-tert-butylpyridine) / g.

[0072] In the method described, the preferred amount of acid on the outer surface of catalyst I in step 1) is 20–40 μmol (2,6-Di-tert-butylpyridine) / g.

[0073] The method wherein, in step 1), the mesoporous pore volume of catalyst I is 0.20-0.60 ml / g.

[0074] The method wherein, in step 1), the preferred mesoporous pore volume of catalyst I is 0.30-0.50 ml / g.

[0075] The method wherein, in step 1), the mass content of the catalyst I supported on platinum and palladium is 0.2-0.8 wt%.

[0076] In the method described, in step 1), the catalyst I preferably has a mass content of supported metals platinum and palladium of 0.3-0.6 wt%.

[0077] The method wherein, in step 1), the total acid content of catalyst II is 200–600 μmol (Pyridine) / g.

[0078] The method wherein, in step 1), the mesoporous pore volume of catalyst II is 0.30-0.80 ml / g.

[0079] The method wherein, in step 1), the preferred mesoporous pore volume of catalyst II is 0.30-0.60 ml / g.

[0080] The method wherein, in step 1), the mass content of the catalyst II supported on platinum and palladium is 0.1-0.6 wt%.

[0081] In the method, wherein the catalyst II in step 1) preferably has a mass content of 0.2-0.5 wt% supported on platinum and palladium.

[0082] In the method described, in step 1), catalysts I and II are combined in a manner where I is on top and II is below, and the reaction raw materials flow through I and II sequentially.

[0083] The method wherein, in step 1), the volume ratio of catalyst I to II is 1:10-10:1.

[0084] The method wherein, in step 1), the preferred volume ratio of catalysts I and II is 1:6-6:1.

[0085] The method wherein, in step 2), the supplementary refining reactor is connected in series with the hydroisomerization reactor in step 1), and the hydroisomerized cracked oil flows from the hydroisomerization reactor into the supplementary refining reactor.

[0086] The method described herein, wherein the additional refining reaction conditions in step 2) are: temperature 180-320℃, hydrogen partial pressure 5.0-15.0 MPa, and feedstock oil volume hourly space velocity 0.5-3 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1-1000:1.

[0087] The method wherein, in step 2), the added refining catalyst is composed of a heat-resistant inorganic oxide as a support and a noble metal supported on the support.

[0088] The method wherein, in step 2), the heat-resistant inorganic oxide support used for supplementing the refined catalyst is alumina and / or silicon oxide.

[0089] The method wherein, in step 2), the precious metal supported on the support in the refined catalyst is one or more of platinum, palladium and iridium.

[0090] The method wherein, in step 2), the total content of noble metals supported on the support in the refined catalyst is 0.2-1.0 wt%.

[0091] In the method described, the crude product after hydrogenation saturation in step 2) enters the atmospheric and vacuum distillation system in step 3) for fractionation of the crude product.

[0092] The method described in step 3) is known in the art for its atmospheric and vacuum distillation towers, and typically includes one or more operating units for flash distillation, atmospheric distillation, and vacuum distillation towers to achieve the separation of products with different distillation ranges.

[0093] The method wherein, in step 3), the atmospheric and vacuum distillation system fractionates the crude product to obtain naphtha, diesel and base oil products.

[0094] 1. Preparation of the hydroisomerization catalyst in the examples

[0095] Catalyst I-1 was prepared using a conventional impregnation method: ZSM-23 was used as the support, and platinum chloride aqueous solution was used as the impregnation liquid. After impregnation at room temperature for 10 h with an equal volume, it was dried at 120 °C and calcined at 500 °C to obtain a catalyst with a Pt content of 0.4 wt% (the remainder being molecular sieves), denoted as I-1. The total acidity of catalyst I-1 was 280 μmol (Pyridine) / g, the acidity on the outer surface was 30 μmol (2,6-Di-tert-butylpyridine) / g, and the mesopore volume was 0.40 ml / g.

[0096] Catalyst I-2 was prepared using a conventional impregnation method: ZSM-23 was used as the support, and an aqueous palladium chloride solution was used as the impregnation liquid. After impregnation at room temperature for 10 hours with an equal volume, the catalyst was dried at 120℃ and calcined at 500℃ to obtain a catalyst with a Pd content of 0.6 wt% (the remainder being molecular sieves), denoted as I-2. The total acidity of catalyst I-2 was 360 μmol (Pyridine) / g, the acidity on the outer surface was 40 μmol (2,6-Di-tert-butylpyridine) / g, and the mesopore volume was 0.50 ml / g.

[0097] Catalyst II-1 was prepared using a conventional impregnation method: ZSM-22 was used as the support, and platinum chloride aqueous solution was used as the impregnation liquid. After impregnation at room temperature for 10 h, the catalyst was dried at 120 °C and calcined at 500 °C to obtain a catalyst with a Pt content of 0.3 wt% (the remainder being molecular sieves), denoted as II-1. The acidity of catalyst II-1 was 500 μmol (Pyridine) / g, and the mesopore volume was 0.35 ml / g.

[0098] Catalyst II-2 was prepared using a conventional impregnation method. Palladium chloride aqueous solution was used as the impregnation solution. After impregnation at room temperature for 10 hours with an equal volume, the catalyst was dried at 120℃ and calcined at 500℃ to obtain a catalyst with a Pd content of 0.5 wt% (the remainder being molecular sieves), denoted as II-2. Catalyst II-2 had an acidity of 300 μmol (Pyridine) / g and a mesopore volume of 0.55 ml / g.

[0099] 2. Preparation of the supplementary refining catalyst HDF-1 in the examples

[0100] The supplementary refined catalyst HDF-1 was prepared using a conventional impregnation method: using alumina as a support and an aqueous solution containing platinum chloride and nickel chloride as the impregnation liquid, the catalyst was impregnated in equal volumes for 10 hours at room temperature, and then dried at 120℃ and calcined at 500℃ to obtain a catalyst with a Pt content of 0.3wt% and a Ni content of 0.5wt% (the remainder being molecular sieves), which was designated as HDF-1.

[0101] The information and preparation method of the hydroisomerization catalyst and the supplementary purification catalyst used in the comparative example of this invention are as follows:

[0102] 3. The hydroisomerization catalysts DI-1, DI-2, DII-1, and DII-2 in the comparative examples

[0103] The hydroisomerization catalyst DI-1 was prepared using a conventional impregnation method. It was supported by ZSM-23 molecular sieve with an MTT structure, and platinum was the active component. Based on the weight percentage of the catalyst, the platinum content was 0.2 wt%, with the remainder being molecular sieve. The total acidity of catalyst DI-1 was 580 μmol (Pyridine) / g, the external surface acidity was 120 μmol (2,6-Di-tert-butylpyridine) / g, and the mesopore volume was 0.20 ml / g.

[0104] The hydroisomerization catalyst DI-2 was prepared using a conventional impregnation method. The catalyst used EU-1, a molecular sieve with an EUO structure, as a support, and platinum as the active component. Based on the weight percentage of the catalyst, the platinum content was 0.2 wt%, with the remainder being molecular sieves. The total acidity of catalyst DI-2 was 650 μmol (Pyridine) / g, the external surface acidity was 170 μmol (2,6-Di-tert-butylpyridine) / g, and the mesopore volume was 0.23 ml / g.

[0105] The hydroisomerization catalyst DII-1 was prepared using a conventional impregnation method. The catalyst was supported on a molecular sieve ZSM-22 with a TON structure, and palladium was the active component. Based on the weight percentage of the catalyst, the palladium content was 0.4 wt%, with the remainder being molecular sieves. The acidity of catalyst DII-1 was 700 μmol (Pyridine) / g, and the mesopore volume was 0.15 ml / g.

[0106] The hydroisomerization catalyst DII-2 was prepared using a conventional impregnation method. The catalyst was supported on ZSM-35 molecular sieve with a FER structure, with palladium as the active component. Based on the weight percentage of the catalyst, the palladium content was 0.5 wt%, with the remainder being molecular sieve. The acidity of catalyst DII-2 was 150 μmol (Pyridine) / g, and the mesopore volume was 0.18 ml / g.

[0107] In the embodiments of this invention, a Fischer-Tropsch synthetic soft wax is used as a raw material, the properties of which are shown in Table 1.

[0108] Table 1 Properties of Fischer-Tropsch Synthetic Soft Wax Feedstock Oil

[0109] project raw material <![CDATA[Density (15 °C), kg / m 3 > 826 Sulfur content, ppm <5 Nitrogen content, ppm <5 Olefin content, wt% 5.5 <![CDATA[Water content, μg·g -1 > 30 Distillation, ℃ Initial boiling point 282 10％ 336 30％ 362 50％ 391 70％ 439 90％ 550 95％ 616 Final boiling point 678

[0110] The simplified process flow diagram of this invention is as follows: Figure 1 As shown.

[0111] Example 1

[0112] The hydroisomerization reactor uses hydroisomerization catalysts I-1 and II-1, with I-1 on top and II-1 below, in a volume ratio of 1:1. The reaction conditions are 333℃, 10MPa, and a space velocity of 0.8h⁻¹. -1 The hydrogen-to-oil ratio was 500; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 220℃, 10MPa, and space velocity 1.0h. -1 The hydrogen-to-oil ratio is 500. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0113] Example 2

[0114] The hydroisomerization reactor uses hydroisomerization catalysts I-1 and II-1, with I-1 on top and II-1 below, in a volume ratio of 1:2. The reaction conditions are 330℃, 8MPa, and a space velocity of 1.0 h⁻¹. -1 The hydrogen-to-oil ratio was 600; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 8MPa, and space velocity 1.5h⁻¹. -1 The hydrogen-to-oil ratio is 600. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0115] Example 3

[0116] The hydroisomerization reactor uses hydroisomerization catalysts I-1 and II-1, with I-1 on top and II-1 below, in a volume ratio of 1:3. The reaction conditions are 326℃, 6MPa, and a space velocity of 0.9h⁻¹. -1 The hydrogen-to-oil ratio was 800; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 6MPa, and space velocity 1.3h / h. -1 The hydrogen-to-oil ratio is 800. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0117] Example 4

[0118] The hydroisomerization reactor uses hydroisomerization catalysts I-2 and II-2, with I-2 on top and II-2 below, in a volume ratio of 2:1. The reaction conditions are 338℃, 7MPa, and a space velocity of 0.8h⁻¹. -1 The hydrogen-to-oil ratio was 700; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 260℃, 7MPa, and space velocity 1.6h⁻¹. -1 The hydrogen-to-oil ratio is 700. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0119] Comparative Example 1

[0120] A similar process flow to that in this embodiment was adopted. The hydroisomerization reactor used hydroisomerization catalysts D and DII-1, with DI-1 on top and DII-1 below, at a volume ratio of 1:1. The reaction conditions were 333°C, 10 MPa, and a space velocity of 0.8 h⁻¹. -1 The hydrogen-to-oil ratio was 500; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 220℃, 10MPa, and space velocity 1.0h. -1 The hydrogen-to-oil ratio is 500. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0121] Comparative Example 2

[0122] A similar process flow to that in this embodiment was adopted. The hydroisomerization reactor used hydroisomerization catalysts DI-2 and DII-2, with DI-2 on top and DII-2 below, at a volume ratio of 1:2. The reaction conditions were 330°C, 8 MPa, and a space velocity of 1.0 h⁻¹. -1 The hydrogen-to-oil ratio was 600; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 8MPa, and space velocity 1.5h⁻¹. -1 The hydrogen-to-oil ratio is 600. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0123] Comparative Example 3

[0124] A similar process flow to that in this embodiment was adopted. The hydroisomerization reactor used the hydroisomerization catalyst DI-1, and the reaction conditions were 325°C, 12 MPa, and a space velocity of 0.8 h⁻¹. -1 The hydrogen-to-oil ratio was 500; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 12MPa, and a space velocity of 1.0 h⁻¹. -1 The hydrogen-to-oil ratio is 500. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0125] Comparative Example 4

[0126] A similar process flow to that in this embodiment was adopted. The hydroisomerization reactor used the hydroisomerization catalyst DII-1, and the reaction conditions were 340°C, 10 MPa, and a space velocity of 0.8 h⁻¹. -1 The hydrogen-to-oil ratio was 600; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 10MPa, and space velocity 1.2h⁻¹. -1 The hydrogen-to-oil ratio is 600. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0127] Comparative Example 5

[0128] A similar process flow to that in this embodiment was adopted. The hydroisomerization reactor used hydroisomerization catalyst I-1 (i.e., I-1 in Example 1), and the reaction conditions were 346°C, 6 MPa, and a space velocity of 0.9 h⁻¹. -1 The hydrogen-to-oil ratio was 800; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 240℃, 6MPa, and space velocity 1.3h / h. -1 The hydrogen-to-oil ratio is 800. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0129] Comparative Example 6

[0130] A similar process flow to that used in this embodiment was employed. The hydroisomerization reactor used hydroisomerization catalysts DI-1 and II-1 (i.e., II-1 in Example 1), with DI-1 on top and II-1 below. The reaction conditions were 338°C, 7 MPa, and a space velocity of 0.8 h⁻¹. -1 The hydrogen-to-oil ratio was 700; the supplemental refining reactor used supplemental refining catalyst HDF-1, and the reaction conditions were 260℃, 7MPa, and space velocity 1.6h⁻¹. -1 The hydrogen-to-oil ratio is 700. The product yields obtained after the feedstocks shown in Table 1 are shown in Table 2 after conversion and fractionation in this reaction process, and the properties of the base oil products are shown in Table 3.

[0131] As shown in Table 2, compared with the comparative example, the method described in this invention significantly improves the base oil yield while significantly reducing the yields of lower-value gaseous hydrocarbons, naphtha, and diesel. Meanwhile, as shown in Table 3, compared with the comparative example, the base oil products in the examples have lower pour points, higher viscosity indices, higher flash points, and better stability.

[0132] Table 2 Product Yield

[0133]

[0134] Table 3 Properties of Base Oil Products

[0135]

[0136] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A hydroisomerization catalyst, characterized in that, The hydroisomerization catalyst is a composite catalyst, comprising catalyst I and catalyst II; Catalyst I is a molecular sieve catalyst with an MTT structure supported on platinum and / or palladium. Catalyst II is a molecular sieve catalyst with a TON structure supported on platinum and / or palladium. The catalyst I and catalyst II are combined in such a way that catalyst I is located on top of catalyst II.

2. The hydroisomerization catalyst according to claim 1, characterized in that, The catalyst I has a total acid content of 100–400 μmol / g, an external surface acid content of 10–50 μmol / g, a mesopore volume of 0.20–0.60 ml / g, and a platinum and / or palladium loading of 0.2–0.8 wt%. The molecular sieve with the MTT structure is selected from at least one of ZSM-23, Me-ZSM-23, EU-13, KZ-1, and ISI-4; wherein, Me-ZSM-23 is a ZSM-23 molecular sieve doped with metal heteroatoms Me, and Me is selected from at least one of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd, or Ni.

3. The hydroisomerization catalyst according to claim 1, characterized in that, The total acid content in catalyst II is 200–600 μmol / g, the mesoporous pore volume is 0.30–0.80 ml / g, and the platinum and / or palladium loading is 0.1–0.6 wt%. The molecular sieve with the TON structure is selected from at least one of ZSM-22, Me-ZSM-22, Theta-1, KZ-2, ISI-1, and NU-10; wherein, Me-ZSM-22 is a ZSM-22 molecular sieve doped with metal heteroatoms Me, and Me is selected from at least one of Zn, Mg, Mn, Co, Cr, Cu, Fe, Cd, or Ni.

4. The hydroisomerization catalyst according to claim 1, characterized in that, The volume ratio of catalyst I to catalyst II is 1:10-10:1; preferably, the volume ratio of catalyst I to catalyst II is 1:6-6:

1.

5. A method for producing lubricating oil base oil by hydrogenation of Fischer-Tropsch synthetic soft wax as raw material, characterized in that, Includes the following steps: 1) Fischer-Tropsch synthesized soft wax and hydrogen are mixed and introduced into the hydroisomerization reaction zone, where they come into contact with the hydroisomerization catalyst to carry out the hydroisomerization reaction, and hydroisomerized cracked oil is obtained. 2) The hydroisomerized cracked oil enters the supplementary refining reaction zone and comes into contact with the supplementary refining catalyst, which further hydrogenates and saturates the hydroisomerized cracked oil to obtain the crude product. 3) Fractionate the crude product to obtain products including lubricating oil base oil; The hydroisomerization catalyst mentioned in step 2) is selected from the hydroisomerization catalysts described in any one of claims 1 to 4; The Fischer-Tropsch synthesized soft wax and hydrogen are mixed and then enter the hydroisomerization reaction zone, where they flow sequentially through catalyst I and catalyst II.

6. The method according to claim 5, characterized in that, The step of fractionating the crude product described in step 3) is as follows: the crude product is sequentially fed into an atmospheric distillation tower and a vacuum distillation tower for fractionation to obtain lubricating oil base oil, naphtha and diesel.

7. The method according to claim 5, characterized in that, The supplementary refining catalyst mentioned in step 2) is a supported catalyst containing at least one active component selected from platinum, palladium, and iridium; the support is alumina and / or silica. The active component, at least one of platinum, palladium, and iridium, is present in the supplemental refining catalyst at a mass content of 0.2–1.0 wt%.

8. The method according to claim 5, characterized in that, The reaction conditions for the supplementary purification reaction described in step 2) are as follows: The reaction temperature is 160–360℃, the hydrogen partial pressure is 3.0–18.0 MPa, and the feedstock oil volume hourly space velocity is 0.5–5.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 200:1 to 2000:1; Preferably, the reaction temperature is 180–320°C, the hydrogen partial pressure is 5.0–15.0 MPa, and the feedstock volume hourly space velocity is 0.5–3 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1 to 1000:

1.

9. The method according to claim 5, characterized in that, The n-alkane content in the Fischer-Tropsch synthesized soft wax described in step 1) is not higher than 60%, the unsaturated hydrocarbon content is not lower than 0.5%, the initial boiling point is not lower than 220℃, and the final boiling point is not higher than 750℃. The conditions for the hydroisomerization reaction are: The reaction temperature is 200–450℃, the hydrogen partial pressure is 3.0–18.0 MPa, and the feedstock oil volume hourly space velocity is 0.4–4.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 200:1 to 2000:

1.

10. The method according to claim 5, characterized in that, The n-alkane content in the Fischer-Tropsch synthesized soft wax described in step 1) is not higher than 50%, the unsaturated hydrocarbon content is not lower than 1%, the initial boiling point is not lower than 260℃, and the final boiling point is not higher than 700℃. The hydroisomerization reaction conditions are: temperature 300–400℃, hydrogen partial pressure 5.0–15.0 MPa, and feedstock volume hourly space velocity 0.5–2.0 h⁻¹. -1 The hydrogen-to-oil ratio is 200:1 to 1000:1.

Images